HOW TO UNLOCK SUPERUSER AND LOGIN AS ROOT IN Ubuntu

HOW TO UNLOCK SUPERUSER AND LOGIN AS ROOT

To unlock root us the following command,

1. sudo password root
   
   you will be asked to enter password root password two times.
2. Then unlock root user by following command
   
   sudo password -u root
3. To lock it again use the following command
   
   sudo password -l root
4. To login as root use the following command
   
   su root
   
   you will be asked for given root password
5. To login interactively use the following command
   
   sudo -i
   
   username:  root
   password : ********